Echocardiographic indicators of fluid responsiveness in hospitalized dogs with compromised hemodynamics and tissue hypoperfusion.

OBJECTIVE: To evaluate the accuracy of selected echocardiographic variables used to predict fluid responsiveness in hospitalized dogs with compromised hemodynamics and tissue hypoperfusion. DESIGN: Diagnostic test study in a prospective cohort of hospitalized dogs. SETTING: Veterinary referral clinics. ANIMALS: Forty-four hospitalized dogs with compromised hemodynamics and tissue hypoperfusion were utilized in this study. INTERVENTIONS: Echocardiographic examination before and after fluid replacement with 30 ml/kg of lactated Ringer's solution. MEASUREMENTS AND MAIN RESULTS: Pre-fluid replacement measurements of velocity of transmitral E wave (E-peak), the left ventricular end-diastolic internal diameter normalized to body weight (LVIDdN), and the left ventricular end-systolic internal diameter normalized to body weight (LVIDsN) were significantly lower in fluid-responsive patients compared with nonresponders (P < 0.001). The area under the receiver operating characteristic curve (AUROC) with its 95% confidence interval (CI) for each significant predictor was as follows: E-peak 0.907 (0.776-1.000, P < 0.001) and LVIDdN 0.919 (0.801-1.000, P < 0.001). The predictive capacity of LVIDsN was not significantly better than chance (AUROC, 0.753; 95% CI, 0.472-1.000, P = 0.078). A significant negative linear correlation was observed between the percentage of increase in velocity-time integral after expansion and the echocardiographic variables LVIDdN (rs  = -0.452, P = 0.023) and E-peak (rs  = -0.396, P = 0.008) pre-fluid replacement. The intraobserver and interobserver variability was very low (<5 %) for all measurements. CONCLUSIONS: In this study using critically ill dogs with compromised hemodynamics and tissue hypoperfusion, pre-fluid replacement measurements of LVIDdN and E-peak adequately predict fluid responsiveness. Because a small number of fluid nonresponders were involved in the present study (11.4%), further studies that include larger numbers of fluid-nonresponsive animals are required.

Transient skin and fur color change after trichotomy of the sacrococcygeal region for epidural anesthesia in a domestic cat (Felis catus) / Mudança transitória da cor da pele e pelo após tricotomia da região sacrococcígea para anestesia epidural em gata doméstica (Felis catus)

A clinical case in which skin and hair color change occurred after sacrococcygeal epidural anesthesia in a nine-month-old Siamese cross queen undergoing ovariohysterectomy (OHE) is described. Six weeks after surgery, during a re-check, it was noted that in the sacrococcygeal region the color of the skin and new hair growth was dark with a color comparable to the color present on the body extremities (muzzle, pinnae, legs, and tail). The skin and new hair growth of the shaved abdomen presented a standard color. The key enzyme of the melanogenic pathway in mammals is tyrosinase (TYR), and the Siamese temperature-sensitive phenotype is the result of genetic mutations that makes TYR function thermolabile. The activity of TYR in these cats is limited to the extremities where the temperature is lower while pigment production is impaired in the other body areas. The trichotomy of the sacrococcygeal region performed during wintertime in an outdoor cat was probably the trigger for increased activity of TYR in this area promoting pigment production. The absence of the same alterations in the abdominal area may be justified by less exposure of that region to the external environment, as well as to the feline habits of sedentarism, that avoid significant cooling in these regions. This report highlights the importance of taking this type of occurrence into account when performing an epidural in the Siamese cat breed. Also, to avoid skin color change in this breed, the authors recommend a midline abdominal instead of a flank approach to perform OHE.(AU)

Descreve-se um caso clínico no qual ocorreu mudança na cor da pele e do pelo após anestesia epidural sacrococcígea numa gata cruzada de raça Siamês de nove meses submetida à ovariohisterectomia (OVH). Seis semanas após a cirurgia, durante uma avaliação pós-operatória, notou-se que na região sacrococcígea, a cor da pele e o crescimento do pelo apresentavam uma cor escura, comparável à das extremidades do corpo (face, orelhas, membros e cauda). A pele e o crescimento do pelo do abdómen, que também havia sido tosquiado, apresentavam uma cor padrão. A enzima chave da via melanogênica em mamíferos é a tirosinase (TYR) e o fenótipo siamês sensível à temperatura é o resultado de mutações genéticas que tornam a função TYR termolábil. A atividade da TYR nestes gatos é limitada às extremidades onde a temperatura é mais baixa, enquanto a produção de pigmento é prejudicada em outras áreas do corpo. A tricotomia da região sacrococcígea realizada durante o inverno nesta gata com acesso livre ao ambiente externo, provavelmente determinou um aumento da atividade da TYR nesta área, promovendo a produção de pigmento. A ausência das mesmas alterações na região abdominal pode ser justificada pela menor exposição desta área do corpo ao ambiente externo, também devido aos hábitos felinos de sedentarismo, que evitam resfriamento significativo nestas regiões. Este relato destaca a importância de se levar em consideração a possibilidade deste tipo de ocorrência quando da realização de uma anestesia epidural nesta raça de gatos. Além disso, os autores recomendam uma abordagem abdominal na linha média ao invés de uma abordagem de flanco para realizar a OVH nesta raça, a fim de evitar a alteração da cor da pele.(AU)